Blenheim Palace bosses have pulled the plug on the first and last night of their annual music festival in Woodstock because of poor ticket sales.

But concert-goers have been promised an automatic refund within two weeks.

Organisers have cancelled the bill on June 30, which would have been Italian singer Patrizio Buanne, mezzo-soprano Katherine Jenkins and Tricolore, and Jose Carreras on July 3.

International superstar Diana Ross and rocker Rod Stewart will still take to the stage on July 1 and 2, and tickets are still available.

The news will come as a double blow to the 300 people who had been given free passes to see Jose Carreras at the palace.

Blenheim Palace organisers dished out the tickets to angry Andrea Bocelli fans who were let down when The Very Impressive Party Company cancelled a concert at Kassam Stadium scheduled for April 30. A new date is yet to be confirmed.

John Hoy, Blenheim Palace chief executive, is personally writing to free Carreras ticketholders and offering them the chance to see Diana Ross instead.

He said: "Having to make this decision is the last thing we wanted to do. We are dreadfully sad to have to cancel anything.

"We had to look at the financial situation and it didn't stack up."

Mr Hoy said only 12 per cent of tickets for the Jose Carreras event were sold. He added: "The situation is further complicated by the Bocelli arrangements.

"We fully recognise we are in an embarrassing situation and we will honour our commitment made to those people.

"We don't want what we did to look like some hollow gesture that we didn't carry through."

Ann Hernandez, 60, from Headington, Oxford, was one of many offered a free Carreras ticket. She said: "It was very nice of Blenheim Palace to offer the tickets in the first place but to have a second disappointment again is not good."

She said she was delighted to hear she would receive a ticket to see Diana Ross, adding: "That is really good news."

Dennis Garrett, 64, of Abingdon, was offered three seats at the concert after spending hundreds of pounds on 14 Bocelli tickets.

He said he was happy to see Diana Ross instead, adding: "I'll live with that. Of all the tenors Carreras is not really a favourite. I particularly like Bocelli."

Mr Hoy said he thought ticket sales had been low for various reasons, including the economy slowing down, bad weather, and people being distracted by the General Election.

For information about refunds or buying tickets to see Diana Ross or Rod Stewart call 0870 7460004 or visit www.ticketline.co.uk